#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main() {
	int arr[] = { 1,1,3,3,5,5,8,8,9 };
	int i = sizeof(arr) / sizeof(arr[0]);
	int m = 0;
	for (int j = 0; j < i; j++) {
		m = m ^ arr[j];
	}
	int a = 2 ^ 2;
	printf("%d\n", m);
}